The economy gauge needle on my 85 500 sl euro is mostly in the red at the right side of the gauge. Very little needle movement. Perhaps 1/8 inch. Tranny seems to shift late too, although recently O/H. No obvious vacuum leaks. Also car is hard starting sometimes needing 5 to 8 seconds of fast cranking to start. New plugs & wires. Do smell a slight fuel odor but no visible leaking. Compression OK.